I give it a clean through if I use energy drink stuff, if just water I ether just leave it or put it in the freezer every now and again. Occasionally wash it out with Milton.

Only use water, store it in the fridge & give it an overnight soak with denture cleaning tablets. Nice minty taste & cheap as hell from tesco!

only use water and clean every now & then

tip: to clean black gunk from hose get an old gear cable and wrap some paper towel/cotton wool to the end with the round bit of metal. thread & pull through tube a couple of times and you no longer have a black gunk infested tube. 🙂

I use bottles and wash them after every ride.

I can't be arsed with lumping a great big rucksack around with me. What the hell do you lot put in them?